Operating unit for handling moving products

Abstract: An operating unit (1), in the example shown a fantail twisting unit, wherein a feed device (7) with a number of transportation heads (10) for respective products (4), in the example shown products (4) with a wrapping (3) having at least one open end (2), successively feeds the products (4) along a curved path (17a) through an operating station (6), in the example shown a station for closing the wrappings (3), where each product (4) is engaged by a tool (59), in the example shown a mechanical hand, for performing a given operation on the product (4), in the example shown for fantail twisting the open end of the wrapping (3); the tool (59) being fitted to a toolholder device (18) by which it is fed through the operating station (6) simultaneously with a respective product (4) and along the same curved path (17a) along which the product (4) travels.

Description: The present invention relates to an operating unit for handling moving products. Though employable in any technical field for performing one or more operations on moving products or objects in general, the present invention is particularly suitable for use in the confectionary industry, for "fantailing" the wrappings of products, especially sweets and similar, fed substantially continuously along a given path. For this reason, the following description refers specifically, though purely by way of example, to a fantail forming unit of the type comprising a wrapping closing station; a feed device with a given number of transportation heads for feeding the closing station with respective products having a wrapping with at least one open end portion; and a closing device located at the closing station, for fantailing the open end portion of each wrapping, and comprising at least one tool consisting of a mechanical hand revolving about its axis. Operating units of the aforementioned type are known to comprise step operated feed devices, the transportation heads of which are fed successively and in steps through the closing station where, in the event the wrappings present only one open end portion, a single operating hand successively engages the respective open end portions of the wrappings as the respective transportation heads are arrested at the closing station. In the event both the end portions of each wrapping are open, the closing station obviously presents two opposed operating hands. A major drawback of known operating units of the aforementioned type is that, by virtue of being step operated, the operating speed of the units is relatively slow and totally inadequate for the wrapping machines currently available on the market. In an attempt to overcome the above drawback, an operating unit is disclosed in GB-A-2 035 253 featuring a continuously operated feed device, each transportation head of which presents a closing element moving with the head and in turn featuring at least one operating hand. While enabling relatively fast operating speeds, continuously operated units of the above type are invariably expensive and unreliable due to the complex mechanical design of the feed devices and the number of components involved. Moreover, by virtue of the complex mechanical design of the feed devices, the areas in which the wrappings are actually fantailed are rendered substantially inaccessible, and any change in format economically unfeasible. In other words, continuously operated units of the above type are generally expensive and unreliable. It is an object of the present invention to provide an operating unit designed to overcome the aforementioned drawbacks. According to the present invention, there is provided an operating unit for handling moving products, the unit comprising an operating station for performing a given operation on said products; a feed device having a given number of transportation heads for respective said products, and designed to feed the products successively along a first given path through the operating station; and an operating device located at the operating station, for performing said operation on said products, and comprising at least one operating tool, and drive means for moving said tool about a first axis according to a first given law of motion, and along a second, annular, path; characterized by the fact that said drive means comprise a hypocyclic drive; said secon path comprising an active portion substantially coinciding with said first path. According to a preferred embodiment of the above unit, each transportation head moves about a second axis parallel to the first axis; drive means being provided for moving the transportation head according to a second law of motion, substantially similar to the first law of motion, as it travels along said first path. The operating device also preferably comprises a given number of said tools substantially equally spaced about the first axis; the number of the tools being independent of the number of transportation heads. A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a schematic plan view of a preferred embodiment of the operating unit according to the present invention; Figure 2 shows a larger-scale axial section of a detail in Figure 1; Figure 3 shows a larger-scale detail of Figure 2; Figure 4 shows a section along line IV-IV in Figure 2; Figure 5 shows an operating diagram relative to a particular instant in the operation of the Figure 1 unit. Number 1 in Figure 1 indicates an operating unit for performing an operation consisting in fantailing the two open end portions 2 of tubular wrappings 3 of a succession of sweets 4, by twisting portions 2 into respective fantails 5 (Figure 2) at an operating station 6 for closing wrappings 3. Unit 1 comprises a known feed device 7 in turn comprising a drum 8 supported on a fixed frame (not shown) and rotated by a drive shaft (not shown) at substantially constant speed and anticlockwise (in Figure 5) about a substantially horizontal axis 9. From drum 8 there project substantially radially outwards a number of transportation heads 10 equally spaced about drum 8 and each comprising (Figure 5) two jaws 11 movable, via known actuating means (not shown), to and from a closed position in which they grip a sweet 4 positioned with its axis 12 parallel to axis 9 and having a respective wrapping 3. As shown in Figure 5, each head 10 is fitted to drum 8 so as to rotate, in relation to drum 8, about a pivot 13 parallel to axis 9 and by virtue of the torque applied to head 10 by a lever 14 fitted on its free end with a tappet roller 15 moving along a fixed cam 16. As it rotates about axis 9, drum 8 feeds sweets 4 successively along a substantially circular path 17 comprising a curved portion 17a extending through station 6 and along which sweets 4 are fed with a law of motion determined, at each instant, by the sum of a first speed vector due to rotation of drum 8 about axis 9, and a second speed vector due to rotation by cam 16 of respective head 10 about respective pivot 13, so that said law of motion may be varied in any way by simply varying the design of cam 16. Unit 1 also comprises a closing device 18 at station 6, for fantailing each end portion 2 of each wrapping 3. As shown in Figure 1, closing device 18 comprises a fixed frame 19 integral with the frame (not shown) supporting drum 8, and having a fixed wall 20 extending perpendicular to axis 9 and coplanar with transportation heads 10. Wall 20 is located at station 6, and presents a free edge which, as shown particularly in Figure 5, is skimmed by sweets 4 as they travel through station 6. Wall 20 constitutes the main bearing of a shaft 21 having an axis 22 parallel to axis 9 and mounted for rotation through a hole 23 in wall 20 via the interposition of a bearing 24. Shaft 21 is a central shaft for driving and synchronizing two identical closing elements 25 arranged specularly on either side of wall 20. Both elements 25 are only required in the event wrappings 3 present two open end portions 2. If only one open end portion 2 is involved, one of elements 25 may be eliminated, for which purpose shaft 21 is formed in two parts connected by a removable joint at hole 23. In view of the identical design of elements 25 and the fact that, as stated, one may be dispensed with, only one of elements 25 will be described below with reference to Figures 2 and 3. Element 25 comprises a substantially U-shaped support 26 integral with and having its concavity facing frame 19. Support 26 presents an inner wall 27 through which is fitted a tubular body 28 coaxial with axis 22 and fitted integral with a fixed drum 29 on the end facing wall 20. Internally and via the interposition of a bearing 30, body 28 supports for rotation the free end portion 31 of shaft 21, and presents, inside support 26, an opening through which a gear 32, fitted to portion 31 of shaft 21, meshes with a first gear 33 of a reducer housed inside support 26 and comprising, in addition to gear 33, a second gear 34 smaller in diameter than gear 33. Gear 34 is coaxial with gear 33, and is mounted on support 26 so as to rotate with gear 33 about an axis 35 parallel to axis 22 and by virtue of a drive gear 36 meshing with gear 33 and synchronized, in known manner (not shown) and according to a given law, with the drive shaft (not shown) of drum 8. Element 25 also comprises a bell 37 defined laterally by a cylindrical wall 38 coaxial with axis 22 and closed at one end by a wall 39 perpendicular to axis 22. Wall 39 presents a tubular axial appendix 40 facing support 26 and fitted through with body 28, which supports for rotation appendix 40 and bell 37 via the interposition of a bearing 41. An end portion of appendix 40 penetrates inside support 26 and is fitted with a gear 42 meshing with gear 34 for rotating bell 37 about axis 22 in the same direction as shaft 21, but at a slower speed by virtue of the smaller number of teeth on gear 34 as compared with gear 33. At the end facing wall 20 and opposite to that featuring appendix 40, bell 37 is closed by a thick plate 43 having a central, substantially cylindrical through hole 44 coaxial with axis 22 and engaged in rotary manner by a further portion 45 of shaft 21 via the interposition of bearings 46. Plate 43 also presents four holes 47 having respective axes 48 parallel to and equally spaced about axis 22. Via the interposition of bearings 49, each hole 47 houses for rotation the cylindrical body 50 of a gripping device 51 rotated about respective axis 48 by a sun gear 52 formed on shaft 21 between plate 43 and drum 29 and meshing with a planetary gear 53 formed on the end of body 50 facing wall 38. Each body 50 presents a hole 54 having an axis 55 parallel to and eccentric in relation to respective axis 48; and the central portion of each body 50 presents an opening 56 communicating laterally with hole 54 and engaged by a ring gear 57 formed on the inner surface of respective hole 47. Each hole 54 houses in rotary and axially-sliding manner the tubular, substantially cylindrical head 58 of a mechanical operating hand 59. In addition to head 58, hand 59 also comprises two opposed jaws 60 pivoting on the end of head 58 facing wall 20, and connected, by means of a rack and pinion drive 61, to a cup-shaped body 62 mounted in axially-sliding manner inside head 58 so as to move jaws 60 in opposite directions between an open position (bottom of Figure 2) and a closed position (top of Figure 2). Each hand 59 also comprises a shaft 63 coaxial with axis 55, mounted in axially-sliding manner through head 58, and connected at one end to respective body 62 via the interposition of an elastic axial joint 64. An intermediate outer surface portion of each head 58 presents teeth 65 meshing, through opening 56, with ring gear 57 so that, as body 50 is rotated inside respective hole 47, head 58 is rotated in the opposite direction about axis 55 by virtue of teeth 65 rolling along ring gear 57. Finally, each hand 59 comprises a first actuating device 66 for cyclically moving respective head 58 axially along respective hole 54 towards wall 20, and between an idle withdrawn position (bottom of Figure 2) and a forward gripping position (top of Figure 2); and a second actuating device 67 for axially moving shaft 63 and body 62 in relation to head 58 and so moving jaws 60 between said open and closed positions. Actuating devices 66 and 67 present a common shaft 68 coaxial with axis 48 and having a first end facing wall 39 and housed in rotary and axially-sliding manner inside a seat 69 formed through a plate 70 integral with wall 39; and a second end facing wall 20, housed in axially-sliding manner inside an axial cavity 71 on the end of body 50 facing wall 39, and fitted integral with a bracket 72 fitted axially and in rotary manner, via the interposition of a bearing 73 coaxial with axis 55, to the end of respective head 58 facing wall 39. Connection of bracket 72 and respective head 58 - eccentric in relation to axis 48 - provides for rendering shaft 68 and respective body 50 angularly integral with each other. Sliding connection of shaft 68 and body 50 at cavity 71 is assured by a sleeve 74 mounted in sliding manner on shaft 68 and presenting, on the end facing wall 20, a plate 75 through which are fitted an eccentric guide pin 76 housed inside cavity 71 and parallel to axis 48, and an end portion of shaft 63 fitted axially to plate 75. The portion of shaft 68 between sleeve 74 and seat 69 engages in rotary and axially-fixed manner a cylindrical sleeve 77 forming part of actuating device 66 and having two radial pins 78 and 79, the first supporting in idle manner a tappet roller 80 moving inside a cam groove 81 formed on the outer surface of drum 29, and the second engaging in sliding manner a guide and angular lock opening 82 formed parallel to axis 22 on an appendix 83 of plate 70. The end portion of sleeve 74 opposite that with plate 75 presents an annular fork 84 engaged by a roller 85 constituting the output member of actuating device 67. As shown more clearly in Figure 4, actuating device 67 comprises a rocker arm 86 having a central transverse hinge pin 87 fitted in rotary and axially-fixed manner through a hole 88 in a supporting body 89 integral with wall 38 of bell 37, and having an axis 90 substantially radial in relation to wall 38. Rocker arm 86 presents a first end fitted with a pin 91 parallel to axis 90 and supporting roller 85 in idle manner; and a second end fitted with a further pin 92 parallel to pin 91 and supporting in idle manner a further tappet roller 93 engaging a cam groove 94 formed on the outer surface of drum 29. In actual use, gears 33 and 34, driven by gear 36, rotate shaft 21 and bell 37 clockwise in Figure 5, and, by virtue of the different gear ratio, shaft 21 rotates about axis 22 at a greater speed as compared with bell 37. As bell 37 rotates, axis 48 of each hole 47 travels, clockwise in Figure 5, along a circular path 95 which, at closing station 6, intersects portion 17a of path 17 of sweets 4 at two points. Groove 81 is so designed that, for each turn of bell 37 about axis 22, each operating hand 59 moves between a forward position, assumed as it travels through station 6 and wherein jaws 60 are so positioned as to engage portion 2 of wrapping 3 of a respective sweet 4, and a withdrawn position assumed outside station 6. Groove 94 is so designed that, for each turn of bell 37 about axis 22, jaws 60 of each operating hand 59 move between a closed position, assumed as they travel through station 6 and wherein jaws 60 provide for gripping portion 2 of wrapping 3 of a respective sweet 4, and an open position assumed outside station 6. As shown in Figure 5, sun gear 52, planetary gears 53 and eccentric heads 58 on planetary gears 53 define a hypocyclic drive 96 which, for each turn of bell 37 about axis 22, moves each axis 55 about axis 22 along a substantially quadrangular path 97 having curved sides 98, the shape of which is a function of the eccentricity of axes 55 in relation to respective axes 48. More specifically, in the case of only a very small degree of eccentricity, the sides of path 97 present their respective concavities facing axis 22; and, as the eccentricity increases, the sides first become substantially straight and then curve increasingly towards axis 22. By adjusting the eccentricity of axes 55 in relation to respective axes 48, therefore, a path 97 can always be found wherein one side 98a, extending through station 6, coincides with portion 17a of path 17. As the traveling speed of axes 55 along sides 98, instead of being constant, varies according to a given law of motion which is also a function, among other things, of the eccentricity of axes 55 in relation to respective axes 48, cam 16 must be so designed that axes 12 travel along portion 17a according to the same law of motion. In which case, it is sufficient to so synchronize the speed and operation of drum 8 and bell 37 that each hand 59 travels through station 6 together with a respective sweet 4, the open end portion 2 of wrapping 3 of which is gripped by jaws 60 at the input of station 6, and is twisted into a fantail as jaws 60 are rotated by respective teeth 65 rolling along respective ring gear 57. The advantages of unit 1 as compared with the known state of the art will be clear from the foregoing description. In particular, closing devices 18 are fully independent of feed device 7; are extremely compact and relatively cheap; provide for full exposure and access to device 7, even at closing station 6; and may be changed easily, for servicing or different product sizes, with absolutely no alteration to feed device 7 with the exception of cam 16. By virtue of the relatively light weight of devices 18, and the fact that each operating hand 59 accompanies sweet 4 part of the way through station 6, devices 18 may be rotated extremely rapidly, despite allowing sufficient time for fantailing the open end portions 2 of wrappings 3, and as such may be connected to high-speed feed devices 7, despite the number of gripping devices 51 differing from the number of transportation heads 10 on device 7. The fact that the number of gripping devices 51 is independent of transportation heads 10 enables closing devices 18 to be produced with a relatively small number of devices 51 for reducing production and maintenance costs.

Claims: An operating unit (1) for handling moving products (4), the unit comprising an operating station (6) for performing a given operation on said products (4); a feed device (7) having a given number of transportation heads (10) for respective said products (4), and designed to feed the products (4) successively along a first given path (17a) through the operating station (6); and an operating device (18) located at the operating station (6), for performing said operation on said products (4), and comprising at least one operating tool (59), and drive means (96) for moving said tool (59) about a first axis (22) according to a first given law of motion, and along a second, annular, path (97); characterized by the fact that said drive means (96) comprise a hypocyclic drive (96); said secon path (97) comprising an active portion (98a) substantially coinciding with said first path (17a). A unit as claimed in Claim 1, characterized by the fact that each transportation head (10) is movable about a second axis (9) parallel to the first axis (22); actuating means (16) being provided for moving the transportation head (10) according to a second law of motion, substantially the same as the first law of motion, as the transportation head (10) travels along said first path (17a). A unit as claimed in Claim 1 or 2, characterized by the fact that the operating device (18) comprises a given number of said tools (59) substantially equally spaced about the first axis (22); the number of the tools (59) being independent of the number of transportation heads (10). A unit as claimed in any one of the foregoing Claims, characterized by the fact that said second path (97) is a quadrangular path, one side (98a) of which coincides with said first path (17a). A unit as claimed in Claim 4, characterized by the fact that said side (98a) is curved with its concavity facing outwards towards the second axis (9). A unit as claimed in anyone of the preceding Claims, characterized by the fact that said hypocyclic drive (96) comprises a sun gear (52) coaxial with the first axis (22); a carrier element (37) rotating about the first axis (22); and, for each tool (59), a planetary gear (53) rotating about a third axis (48) parallel to the first axis (22). A unit as claimed in Claim 6, characterized by the fact that each tool (59) extends along a fourth axis (55) parallel to the first axis (22); said drive (96) also comprising, for each said tool (59), a supporting body (50) integral with the respective planetary gear (53) and rotating with the planetary gear (53) in relation to the carrier element (37) and about the respective third axis (48); each fourth axis (55) being eccentric in relation to the respective third axis (48).

Inventors: SPATAFORA MARIO, SPATAFORA, MARIO
Applicants: AZIONARIA COSTRUZIONI ACMA SPA, AZIONARIA COSTRUZIONI MACCHINE AUTOMATICHE-A.C.M.A.-S.P.A.
Application year: 1994
Main classification: B65B51
IPC codes: B65B25, B65B51